Answer-1: Currently there is no direct class to hide. You can override header.php template to hide that line. Follow https://www.shamimsplugins.com/docs/front-end-pm/customization/change-templates-2/ to change template.
or wait for next version. I will add a class there so that you can easily hide that line with css.

Answer-2:
It will automatically redirect you to message page where you can read that message. Redirect to any other page add following code in your theme’s (child theme’s if any) functions.php (Change YOUR CURRENT MESSAGE PAGE URL and YOUR DESIRE PAGE URL accordingly)

add_filter( 'fep_header_notification', function( $show ){
    $show = str_replace( 'YOUR CURRENT MESSAGE PAGE URL', 'YOUR DESIRE PAGE URL', $show);
    return $show;
});